The Atchafalaya River Delta. Report 7. Analytical Analysis of the Development of the Atchafalaya River Delta.
Abstract
The diversion of fresh water and sediments from the Mississippi River to the Atchafalaya River is developing a new delta on the south-central Louisiana coast. The building of this new wetland area has prompted scientific interest in predicting delta evolution. This study reports the analytical prediction of future delta growth based on the theory of turbulent jets that issue from river outlets and discharge into quiescent bays. An integrated form of the hydrodynamics equations of flow continuity and momentum balance, coupled with the advection-diffusion mass transport equation, have been formulated into a two-dimensional spatial domain. Closed-form analytical solutions are obtained with the aid of similarity functions for the velocity and sediment concentration profiles. A numerical procedure for estimating the area and volume of deposition of the delta sediments is presented. The results show that the deposited sediment forms a saddle-shaped bottom. Rapid accumulatin of suspended sediment near the river outlet and an abrupt decline of sediment deposition away from the outlet observed. It is concluded that the riverine inflow has a insignificant influence of sediment deposition within a short longitudinal distance, and that beyond that distance the riverine inflow is insignificant. The analytical predictions are compared with the predictions made by other statistical and generic approaches; an agreement is found. A sensitivity analysis is performed to assess the relative imporatance of various parameters in the river-bay-delta system. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1985
- Accession Number
- ADA164931
Entities
People
- Flora C. Wang
Organizations
- Louisiana State University